A New Sea Ice Thread

Sea ice threads always seem to be popular. For people interested in handling data themselves, I’ve updated my utility functions for reading sea ice data here. It contains methods for accessing JAXA, monthly NOAA and NSIDC binary. (The latter works but I haven’t verified the turnkey version. Jeff Id has some related tools.)

Here’s a plot for sea ice through May 2009 for the two hemisphere and global using the script below. As you can see, through May 2009, there is virtually no overall trend with an upward trend in SH sea ice offsetting a downward trend in NH sea ice. The MAy 2009 GLB anomaly is relatively elevated, arising from a highish SH anomaly, while even the NH anomaly was (perhaps surprisingly) more or less at the long-term.

I think the real issue will be whether 2009 extent will be above or below 2008. Right now it’s running just above average the 2003-2008 for JAXA.

Steve there is an R-forge site out there which is similar in philosophy to Source Forge. Basically hosting open source code projects. If there is enough interest would you be willing to provide some of your code for a set of packages such as for sea ice and some of your other projects? And anyone else who might have some code they would be willing to provide (Jeff? Ryan?).

From Fig 1 of the header, I’ve flipped the graph for one hemisphere and superimposed. I’ve put blue bars along the X-axis where the corrspondence does not look so good. Do you think there’s much of a mirror at work?

Re: Gary Strand (#24), Putting aside that Steve already got a little peeved at me for inserting my opinion of “uselessness” (Sorry, I really should have let the data speak for itself) but why is the graph “misleading”? Do you have a better, less “misleading” graph to show how I am “misleading” people? I have no intention to “mislead” anyone, so if there is a problem with the graph you really should know that I am, honest to goodness, totally ignorant of it. Enlighten me.

What’s weird is that except for Antarctic, none look like CT’s graphs:
Their global is definitely not flat (the decrease in Arctic is greater than the increase in Antarctic) and recent data in the Arctic are most certainly not at the long term average. What gives?

CT’s graphs are area while the graphs above are extent. Area, at the minimum at least, has dropped faster than extent. CT uses a 1979 to 2000 average to calculate anomalies and according to the R script, the graphs above use an average of all the data which would be somewhat lower than the 1979-2000 average for the NH and higher for the SH so the anomalies would be centered differently.

So you don’t consider Greenland as being in the Arctic? According to GRACE measurements reported by Cazenave, et. al. 2009, Greenland has lost 136 +/- 18 gigatons of ice per year from 2003-2008 and Antarctica has lost 198 +/-22 gigatons/year over the same period resulting in about 1mm/year of the total 2.5 mm/year rise in sea level over the same period. Other land based ice contributed an additional 1.1 mm/year and thermal expansion made up the rest.

It’s somewhat misleading because it’s showing Sep sea ice minimum only, the scenario isn’t specified, and while it’s fun to show spaghetti, perhaps the multimodel average and spread would be more informative.

All that said, it’s not evidence for the previous assertion that AGW mandates that sea ice monotonically decrease.

Re: Gary Strand (#22), Since the er, off topic stuff got a whole string of posts deleted, including my attempt to make it clear that the graph was meant to support your claim, not refute it, I thought I’d say again, I was not trying to contradict you at all-quite the opposite. Cheers.

It’s nice to have a new thread, thanks Steve, though we always get the chaff effect at the start of course, people talking about something that is better placed elsewhere (hint). They tend to disperse along with the ice of course over time ….

Gary asked: What would you guess for the Sep minimum? I’m betting ice cream on 4.33 million km^2.

Gary that sounds good to me though I remain confused about the relationship of the *current anamoly* to the *expected anamoly* on other dates. Does that number tend to stay constant even as the extent swings wildly?

Re: Joe Hunkins (#30), I’m not quite sure what you mean. Usually, if the extent is anomalously low before melt season gets strongly underway, then one can expect the Sep minimum to be anomalously low. However, sea ice is strongly impacted by weather conditions – temps, winds, and so on. For example, as shown in this “figure, the ice was near climatology in late April and early May, but more recently has dropped to +/-2σ of the 79-00 mean.

Basically, sea ice is a “fragile” thing and often reacts strongly to transient weather conditions.

Just looking for help here. On considering the definitions of Ice Extent and Ice Area, it seems IMO the latter should be a better proxy for ice volume, and hence a better reflection of temperature effects. I would expect ice EXTENT to be a strong function of local weather, including currents and wind, which could vary significantly from year to year. Theoretically one could see a decrease in ice extent while the ice volume is actually increasing or vice versa. That would seem to suggest that variability in Extent, and hence normalised amplitudes of anomalies, should be greater than that for Area. This appears to be reflected in the data although I have not attempted to quantify this. And yet, there appears to be a strong focus on Extent in the climate debate, rather than there being a clear priority given to the Area data. Am I missing something important here?

Of concern for the western Arctic region for this summer, is the unusual amount of old ice described earlier in Franklin Strait and M’Clintock Channel. This will most certainly prevent the clearing of the Northwest Passage for a fourth consecutive year and affect transit through the Victoria Strait region during late August and early September period.

Question for someone who reads R better than I: How are the global anomalies calculated? Are the anomalies for the NH and SH summed or are the extents summed and anomalies calculated from the total? Would it make a difference?

It looks like the column names in the seaice data table have extent and area have been reversed. Area must always be less than extent. When I write.table, the numbers in the columns labeled area for NH and SH are larger than for the corresponding columns labeled extent.

In the NSIDC section there are a couple of references to files on disk where the slashes all appear to be backwards in the path: “d:/climate/data/seaice/nsidc” ,e.g. I have very little experience with R, so I don’t know if you can get away with that and I haven’t tried that part of the script to see.

The average loss of extent to minimum for JAXA data 2002-2008 from this date is 4780000 km2 +/-2370000. That would mean based on today’s extent a minimum extent for 2009 of 5520000 km2 with a +/- 3 stdev range of 3120000 to 7920000 km2. Average minimum extent(2002-2008) is 5360000 km2 and median extent 5780000 km2. These are just numbers and not a prediction. Trying to correct the overall uncertainty for autocorrelation, uncertainty in the standard deviation caused by the small number of degrees of freedom or prediction interval is pointless, IMO.

I screwed up my spreadsheet. If I’d been paying any attention, I would have realized that the projected extent minimum for 2009 could not be very different from the average. Corrected numbers for 6/23/2009: 5.35 +/-1.84 Mm2. 2008 stayed close to the average until early August. 2009 has been losing extent faster than average lately, but the last two days are about normal for this time of year.

Thanks Dewitt for the last post, I think those values are way too high for minima. There’s been nothing standard about the last 2 years so even a recovery will mean less than the average for the whole JAXA time plot.

Gary Strand:
June 19th, 2009 at 9:42 pm said

“Usually, if the extent is anomalously low before melt season gets strongly underway, then one can expect the Sep minimum to be anomalously low”

but then said

” However, sea ice is strongly impacted by weather conditions – temps, winds, and so on.(snip) Basically, sea ice is a “fragile” thing and often reacts strongly to transient weather conditions”

Make you mind up, plant you flag in the sand, don’t cover all bases. Which is it?

Which way are you betting for this year? This year was quite a good year for max extent over winter.

I don’t want them to be contradictory, they just seemed to be, probably the error of the reader.

I guess from your minima extent prediction that you think this will be an unusual year, where the weather conditions you mention make it lower than the expected value as suggested by the relatively large value for ice extent in March 2009.

Could be. I’m going for 4.7-4.8 or so I think now. I wouldn’t bet icecream on it though, I have little confidence factor for this year 😀

So far 2009 has tracked reasonably well with 2008, except that 2009 has less baby ice. Thus, if all else were equal (temporary weather conditions don’t interfere), I’d think that the minimum extent would be noticeably greater than 2008. So, with complete trepidation, I’ll jump in with a guess of 5.1 million sq. km.

Nice selection of estimates there, including DeWitt’s corrected. I wonder if Shawn, Chris, BarryW and Phil will join the party? I know Phil doesn’t normally have a bash ( big chicken :p ) but maybe we can tempt him out this time…..

Ok, my take is that it’s going to look like 2005 but below it (a real WAG no S involved) which means it’s going to fall between 2008 and the average. I’ll split the difference and go with 5.0. So I’m guessing it will come in third lowest. 2008 didn’t start it’s downward slide until about 2 months from now so we’ve got a ways to go before we see how this plays out. I’m hoping that the yearling ice has been taking it’s vitamins and working out and is going to protect its’ baby ice relatives.

Nice selection of estimates there, including DeWitt’s corrected. I wonder if Shawn, Chris, BarryW and Phil will join the party? I know Phil doesn’t normally have a bash ( big chicken :p ) but maybe we can tempt him out this time…..

I have no problem with a well defined competition with suitable incentives (I won brownies in Lucia’s comp. last summer). What’re the terms, JAXA min extent or Sept. monthly ave?

That’s why there’s four ‘seasons’ when you talk about the variability of the Arctic ice cover: Nov.-Jan refreeze without much variability, late April-July thaw without much variability, Jan-April a lot of variability which depends on the fringes and extra-Arctic ocean ice, July-Nov variability due to what happens to multiyear ice. My main point is that there isn’t much connection between the periods of variability, what happens in the summer isn’t dependent on whether the Bering ice starts to melt next week or last. On July 1st the extent (AMSR) will be ~9.5-10 Mm^2 then the end run will start which will depend on things like how much multiyear ice left via the Fram since last fall etc.

Subsequent discussion with DeWitt extended the lower band to ~9.2 Mm^2, so far looks good?

I see the experts also refer to the Caitlin Expedition for a source of information about sea ice thickness and age. That does not bode well, if you ask me. They also claim ‘a general agreement between Outlook projections and observations in the 2008 effort,’ despite missing the target by a half million square kilometers, which is very similar to the given margin of error in the 2009 May effort. They do give some more info in the lessons learned section, though.

I could write a script to scrape this, but they always take time. Surely I’m not the only person capable of doing this sort of thing. Maybe someone else would contribute a script -as the data set looks interesting.

DeWitt, you were looking for code to process the Uni-Bremen data. What are you looking for specifically: the gridded data or did you want to process that into total extent/area numbers only? I looked at the files and they have a hdf format (which is HDF4 no longer the current version (HDF5) and there doesn’t seem to be any R interface), a geotiff, png and a pdf which are images. The HDF format is not a simplistic flat file but I have been able to read the data descriptor information in R. I was trying to decide how flexible a accessor program would need to be to get to the data you’re looking for.

Area and extent are all I need. Geotiff files are images, but apparently there is a way to convert the image data to area and extent. There was something about non-standard ellipses which is where I gave up.

I was looking around and there is an R package that can access HDF data files, but you have to install HDF first, which didn’t look trivial to me. The instructions all assume that you are compiling the source code with Visual Studio (ideally the free version VS Express would work), but the compiled binaries are available. It just wasn’t clear at all to me how you went about making the various files available. Then there are the compression libraries, ZLIB and SZIP. Then you have to configure the R package installer so it knows where everything is. Too much for a newbie.

HDF4 binaries and/or source code may still be available. I did see something about leaving them up because it was just too much trouble for a long running project to switch file formats in mid-stream as it were.

The only package I could find was one for HDF5 which doesn’t support 4. There is an interface library for JAVA to HDF (the HDFviewer uses it). I looked at trying use the rJava package but I’m only having partial luck with that. One thing I found was that their format isn’t even consistent, some of the files go from 0-1 and some are percentages 0-100%.

The hdf group has a utility for converting hdf4 to hdf5 but it has to be compiled from the source code for a windows box and it’s not at all clear that it’s compatible with the current version (2008) of Visual Studio Express.

JAXA posts an initial number for the day at about 11 PM EDT. The final number for the day is posted at 10 AM EDT the next day. So looking at the time stamp on the post, only the initial number for 6/28 was available at that time. At this time of year, the final number is larger than the initial number.

Re: Steve McIntyre (#83), Here’s my JAXA for julian day 179
I understand the logic behind the use of julian days. In March and April of the year following a leap year, it seems necessary. However, assuming the ice is responding to things like the orbit of the earth around the sun, tilt of the earth’s axis and so forth, would it not make sense, at some point in the year, to recentre the analysis on the summer solstice, or perhaps given the timing of the ice extent minimum on the fall equinox? The summer solstice in 2009 came just 5hrs 46min later than was the case for 2008 (not 24 hours later) and similarly the fall equinox will come on the same date in September at 21:18 instead of 15:44 ( a lag of about 5.5 hours). Hope I don’t sound like a wiseacre.

Steve: Feel free to develop a script implementing this suggestion. As long as sea ice is reported on a daily basis, the present comparison seems adequate for present purposes.

From CT my Bet: We will never see anymore comparisons at Cryosphere Today (because it simply does not suit ice/AGW. It’s not melting even close to recent rates, see NANSEN/DMI). Proof = quoted below from CT
“February 25, 2009 – The SSMI images for many days in 2009 were bad enough that we removed them from this comparison display (see note below and the NSIDC website). There is enough interest in these side-by-side comparison images that we will try to replace them with corresponding images from the AMSR-E sensor in the coming weeks.
February 17, 2009 – The SSMI sensor seems to be acting up and dropping data swaths from time to time in recent days. Missing swaths will appear on these images as missing data in the southern latitudes. If this persists for more than a few weeks, we will start to fill in these missing data swaths with the ice concentration from the previous day or switch over to the higher resolution AMSR-E sensor. Note – these missing swaths do not affect the timeseries or any other plots on the Cryosphere Today as they are comprised of moving composites of at least three days.”

What it does is increase confidence that the ARGO data is correct and OHC has not increased significantly the last few years. It also puts an upper limit on how fast land based ice is melting, i.e. not very.

Speaking of ice melting, the Arctic ice concentration, as measured by the ratio of Cryosphere Today area to JAXA extent, is tracking 2008. For anyone expecting a significant recovery of minimum area, this is not encouraging. OTOH, the Spring average JAXA extent (April, May, June) is higher than any year since 2003. The linear trend line for Spring extent from 2003 to 2009 actually has a positive slope. The trend of the year-to-date average Arctic extent for 2003 to 2009 is still negative though. The Antarctic area rate is slowing faster than usual so the global area anomaly is in negative territory.

Comparing the geographical melting this year up to now it has shifted from the Canadian side to the Russian side, compared to last year, and more closely matches 2007 than 2008. 2007 had a lot less ice in the Chukchi sea region though.

2009 is now the 4th lowest (5th highest) of this series, but is melting quite fast (comparable to 2007 actually). Does anyone know how to plot the daily melting rate as a function of time? I remember I saw such graphs here last year.

Kind of curious to look at Modis shots of the ice and see it cracking up into pieces that must be 10s or even 100s of km accross, but are presumably only a metre or two thick. A scaled down model would be a plate of ice a metre across, but only a hundredth of a millimitre thick.

2009 is now the 4th lowest (5th highest) of this series, but is melting quite fast (comparable to 2007 actually). Does anyone know how to plot the daily melting rate as a function of time? I remember I saw such graphs here last year.

Uh actually no Flanagan. Look at the numbers again (I know you hate when they don’t conform to your preconceived notions) in your own post and see that 2009 is closer in melt raw numbers to both 2003 and 2006 than to 2007. I would hope I don’t have to show you how to subtract.

you’re obviously accusing me of lying about thise numbers, aren’t you? And what do you know exactly of my “preconceived notions”? For these dates, 2009 has the second highest daily melting rate, so my claim that it is “melting quite fast” does not look, in my opinion, to present any bias.

Moreover it is comparable to 2007 at least because only 2007 and 2009 have 100k+ melt rates. And “comparable” doesn’t mean “the closest” – or only in your preconceived opinion of my alleged preconceived notions, if you see what I mean.

I wouldn’t accuse you of lying but picking one day is cherry-picking. Taking any one day doesn’t tell you anything because the variance of the daily change is too large. For example, four days ago 2009’s extent change was smaller than all of the other years. Right now the extent for 2009 is tracking almost right on top of 2008 and is above the average, but, as you can see from the chart 2007, is taking a nose dive though. So the rate is comparable to 2008 if that means anything.

If you want to play semantics with your words and figures then, it melts quite fast every year at this time so what you are implied is simply not accurate.I didn’t accuse you nor imply that you were lying, merely you were incorrect in your math assumptions in your original post I quoted. You clearly implied that 2009 was more comparable to 2007 than other years (since you cited it) which is inaccurate if you look at the raw numbers like I said. Anyone here who doesn’t know your stance on this is clearly not paying attention because you make it quite clear with your eagerness to spin any news which dares to question the AGW point of view. Hope you have a good 4th

OOPS, don’t look now Flanagan but the final figures for 7/1/2009 are now posted and the new number makes your post even more inaccurate because it is now an extent of 9,722,813 km2. That puts in well under 100K in the melt rate and is no longer “comparable” to 2007 in being over the magical 100K number. Keep looking for a corelation in some way and I am sure you will find it! I do agree with BarryW that a one day or even one week melt numbers are pretty insignificant when taken in the total context of the melt season (or freezing season for that matter).

BarryW is correct here and Gerald, Michael and Flanagan are wrong in bringing this argument to the conversation. How can anybody say one day’s results makes anything comparable to anything? You guys just want to pick an AGW fight 😀

I think my viewpoint, of where it is melting, rather than one days values is far more valid, in this case it is more comparable to 2007. Does this mean that 2009 will match 2007 in loss of extent, no it does not. It might suggest and cause a ripple of interest but nothing more.

I wouldn’t wipe my bottom on one days data unless it was a record high. By the way 2008 has a couple of big days coming up however there are quite a few high pressure area’s in that region now which will help melt.

Given the melt pattern being similar to 2007 and the reduction in multiyear ice I wouldn’t be surprised to see another strong melt.

I have to agree. The ice concentration is tracking 2007 and 2008 at this point. Compared to the 1979-2000 average or even 2006, the concentration is three weeks ahead of schedule. See this plot. There is still too little multi-year ice or the ice is too thin or some combination. Add unfavorable weather and things could get really ugly.

Notes on the derivation of the plot: Arctic ice area from 7/2008 is from a personal compilation of the daily current and 1979-2000 average Arctic ice area posted at Cryosphere Today. Area previous to 7/2008 is from Arctic ice area archived by Spreen and Kaleschke at Uni-Hamburg that has been adjusted to agree with Cryosphere Today area from 7/2008 on. Recent Arctic ice extent is from data archived by IARC-JAXA. 1979-2000 average extent was compiled from NSIDC Arctic ice extent data (1978-2006) that was adjusted so that adjusted 2002 to 2006 NSIDC extent agreed with JAXA extent. Concentration is, of course, area/extent. The noise in the average resulting in what looks like two lines is caused by data prior to mid-1987 being only every other day with some years being even and some odd. Eventually I’ll probably do a moving average or something to get rid of the noise.

6/27/09 is the latest area data I have from Cryosphere Today, since I’m far from being able to calculate extent and area from the HDF or tiff files at Uni-Bremen. So even though the extent is higher in 2009 than the same day in 2008 and much higher than 2006, the area is about the same as 2006 and only slightly lower than 2008 so the concentration is lower in 2009 than in 2006 and 2008. Low concentration means more ocean that is only partially covered and thus more likely to melt.

It might well be preliminary results only. But again 2009 had a bad day and (while it could be corrected) has a 100k+ daily melt again, like in 2007. I won’t make any further comment, because some people seem to think I’m trying to draw conclusions about it (which I didn’t of course). Just raw numbers, folks.

Re: Flanagan (#118), Yes, those numbers appear to be increasing the melt rate for 2009 largely being caused by A. strong southerly winds causing (likely) temporary spiking of some areas in the Arctic region B. amount of new ice subject to faster melt rates. The next 45 days will pretty much tell the tale of where we will end up the melt season and I feel reasonably confident in my 4.588 prediction at seasons end

These guys?
With Explorer, the expedition is expected to reach the Bering Strait by mid-September, when we have sailed through the Northeast Passage, an exploit achieved by Nordenskiöld 130 years earlier onboard the sailing vessel Vega.

it is difficult to figure andy out…..is he one of those guys who believes in Global Warming and says he is sad about the ice melting, but then it is all too obvious when it melts that he is very excited about it? even more excited about being “right” than he is sad about the supposed misery and suffering it will cause the poor of the earth?

serious question….not trying to attack, just trying to get a read Andy!

Man made global warming? I guess so in general but I’m not sure how accurate the values are or the outcome. I’m more concerned about reduced biodiversity and population amount to be honest. I don’t really spend too much time arguing about it to be honest, one of the reasons is I am not that expert on it I don’t mind admitting.

In regards to the Arctic I just like watching the numbers and patterns and guessing what the final values will be. In general I think the scientists are fine and my mischievous side would like to see something unusual to happen so it has to be explained or challenge preconceived ideas. I’m not really wishing for a low or high value this year, my wish is to see NW and NE passages open again so a circumnavigation is possible again.

I’m beginning to think that all this breaking thing in 2007 and 2008 is an artifact of the JAXA algorithm. Spreen and Kaleschke’s data at the Uni-Bremen site show no such dramatic change in rate for either 2007 or 2008. With any luck, they’ll be posting the June 2009 data soon and I’ll have a better read. Meanwhile, the ratio of CT area to JAXA extent (average concentration) continues to decline and is now below the 2007 level for this date.

One last time,can you not see that your second link does not agree with your first, or with anyone else for that matter? DMI has extent below 2008 while NANSEN has extent well above 2008. DMI also agrees with JAXA in that respect, NANSEN doesn’t.

What is fascinating is how the uptick in melt seems to start uniformly around this date and you can see it clearly in the weekly totals Flanagan has been posting. We are now definitely in the peak period of when the largest melts start to occur virtually every year as it has gone over 100,000 for 50% of the reporting years (and another year very close to exceeding that amount) .

2009 has had 4 100k days on the trot and the only other year to have that on Jaxa at this time was 2007, 2007 was putting up some very big figures though. Whether it can keep up 100+ is another story. As mentioned above, all this ice that is melting will go anyway so it’s no great shakes, apart from a numerical / statistical interest.

Not necessarily. The latest concentration images show a lot of lower concentration ice in the Arctic Basin, particularly along the 135E longitude. If the weather and ocean circulation is even a little unfavorable then we could still see area below 2007.

Please cite your references at a more detailed level. Your assertion, from the Canadian perspective, is ambiguous. Let’s fix our observation at July 2, 2009 and look at how 2009 fairs against all other years since 1971 in the Western Arctic.

You will note that the single lowest concentration for this date is 1998. I speculate this would be a signature of the record global temperature UAH anomaly associated with the El Nino at that time. From Anthony Watts.

The 1998 UAH anomaly was over 0.7 Celcius. Today it is zero. In 1998 the Western Arctic was roughly 29% below the 1971 to 2000 median for July 2nd. In 2009 it is only 9% below.

As far as the Northwest passage is concerned. Forget about it. Here’s the ice concentrations:

Note also from this image (to June 29th) that the past week had been roughly 3 degrees Celcius below normal.

Mike Bryant: I think you would have to see temperature anomalies significantly higher – for whatever reason – than the observed 1998 level before you would ever see the ice all go away. For now you can rest easy. It isn’t going to happen. Cheers

You can’t just take temperature as a guide though, otherwise 1998 would have the lowest extent record and in fact for the whole arctic for that year the minima was unremarkable. The problem is that you have just selected one area, north of Canada as an overall indicator. You say 2009 is only 9% lower than the median but where was 2007? It was higher. So there is no correlation to the amount of overall ice come the minimain the arctic basin ( either extent or area) from the data you have picked I feel.

You could be right about the NW passage from this information, but you can’t even be certain about that either.

Did you bother to click on the link in my post and see the pretty picture of the entire Arctic Ocean (rather than just the Canadian Archipelago in your graph) from the University of Bremen?

These threads tend to get long and posting images rather than links makes the load times excessive unless you have a fast computer and a fast connection. The Russian side of the Arctic Basin is where it looks like big losses are coming just like 2007. I wouldn’t be so sure about the Northwest Passage either. Look at 7/6/2007 and 7/6/2009 and then compare with 9/24/2007. I’m not saying it will happen, but you certainly can’t rule it out at this point.

And what does the global temperature anomaly have to do with Arctic Sea ice anyway? The UAH NoPol anomaly is far more appropriate. For example, here’s a comparison of the smoothed NoPol anomaly and the smoothed AMO index. Note that while the temperature has dropped some, it’s still a long way from where it was in 1995. I still think that Arctic sea ice will recover, possibly to 1995 to 2000 levels if the AMO index stays negative or near zero, but it won’t happen overnight or in just one year. It took about 15 years to get to this point it will take at least as many to recover.

If you think that makes me an AGWer declaring victory, then you haven’t been reading my posts very long.

The Bremen image is nice, but it makes you think that all ice is the same, and I know you know it is not.

I also know that perception of the pole acting as a unit is what you are referring to in your comparison, yet the comparison makes my point specifically: North America and the Arctic are locally influenced by El Nino. To what extent is a good question, but 1998 was a record heat wave in our arctic due to El Nino, and it’s effects are reflected in the ice record. I am sure that the fact that that signal was not felt other places in the arctic makes my case that you need to look at a confluence of all factors before making an assertion that we are going to be lower than 2007 for example.

It was a regional not a “global” phenomenon. Perhaps you could do some digging into the weather patterns in 2007 for that sea. Check the SST, check air temp, check winds. If it becomes apparent that 2007 and 2009 look simmilar, then I would concede that 2009 could bottom out near the 2008 level. But, my bet is that the stockpile of old and fast ice in the Canadian north won’t melt as much this year.

But, my bet is that the stockpile of old and fast ice in the Canadian north won’t melt as much this year.

The problem is that that stockpile isn’t what it once was and has been receding over the last several years. It’s being disbursed at each end, out the Fram and particularly starting last year significant breakup in the Beaufort sea which I expect to continue this year.

Re: hengav (#157),
You referred to the “the stockpile of old and fast ice in the Canadian north”. That has indeed been decreasing in recent years, this year there was slightly less multiyear ice than the same time last year. Most of the Arctic Basin ice you link to is in fact one and two year ice;

Thanks for the reference. The second page graphic is great. The paper though, is total opportunist cherry picking: ” By March 1 2008, the extent of perennial sea ice was reduced by one million km squared compared to that of the same time in 2007.” Well duh. The majority of the Canadian ice pack is under the influence of the Beaufort Gyre which keeps the multi-er-perennial ice stuck against the arctic islands. The transpolar drift basically whizzes past “above” this sheet. You are right though, if the Gyre was to get stuck and the sheet “pushed off” from the mainland into the drift, we could have a problem. I will even bet you it has happened before, but won’t happen this year.

“AndyW(141): Would you concede that my point on the temperature signal for 1998 in the Western Arctic is valid?”

No, because you do not provide SST’s, wind, cloud cover, thickness, age data. You can’t ask me to do that and then not provide same data requested yourself. You don’t know why it is was less that year apart from it matches the spike on another graph. However the total does not match that spike, so perhaps it is just coincidence? Can you show it is not?

You said

“My point exactly: You cannot look at the polar region as a whole”

No, that is completely wrong, you do have to take into account the arctic as a whole, as you cherry picking the Canadian region only in 1998 shows.

When I have some time I will dig up the historical trends for Northern Canada. I can tell you that living through it, it was warmer. It got the whole Canadian AGW ball rolling, the whole “what’s going to happen to the polar bear?” type of questioning that still goes on now, 10 years later.

I will say it again more politely. In my opinion, it is incorrect to treat an area the size of Canada or Russia as a single entity, simply because of it’s geographical position. Different parts of the arctic react more or less to different effects. In my opinion, the warming trend associated with strong El Nino years shows up as a North American phenomenon only.

I am not cherry picking, I am merely pointing out that a strong natural variable recorded in the satellite record had a noticeable effect. This variable is not present today, decreasing the likelihood of a record melt in 2009.

” I am sure that the fact that that signal was not felt other places in the arctic makes my case that you need to look at a confluence of all factors before making an assertion that we are going to be lower than 2007 for example”.

He didn’t assert, he said could. Anyhow, looking at the charts on Cryosphere and the one I put in the last thread,

I think your 1998 link is completely unfounded and needs a rethink when considering the whole of the Arctic than just one region. As I mentioned before 2007 shows nothing remarkable in the chart of Canadian values you put up, but it was a remarkable year. 2009 is showing locationally wise a similar pattern, so I think it is rash to discount it so early.

An honest question from a plumber:
If every sliver of ice in the arctic melts this summer, will it guarantee that global warming will be catastrophic, or could the melting in some way ameliorate or diminish catastrophic outcomes of warming? This an honest question, please no ad homs only honest thoughtful responses…
Thanks,
Mike

The arctic ice issue has indeed been taken up as a banner for the AGW catastrophe crowd. I don’t personally see a well-established link between Arctic ice and CO2-driven global warming, but that doesn’t stop alarmists from pointing to every crack in the ice as proof of the coming apocalypse.

The climate models don’t predict (er, PROJECT) temperature very accurately; they do a worse job of projecting Arctic ice. Given that the observed temperatures don’t show the necessary positive feedback, we’re really left with just the observation that Arctic ice is receding which correlates only nominally with global temperature. Is it due to CO2 induced warming, or maybe industrial aeresols, or just plain natural variability, all of the above, or something else that we have overlooked?

We do know that the polar bear and pinnipeds use the Arctic ice at various times of the year. Has the decline of summer extent over the satellite era impacted those populations? (*Cue Dr. McCoy: Dammit Jim! I’m a geophysicist, not a veternarian!) I don’t know the answer to that question, and it seems to me that the bilogists don’t know either. Polar bears appear to be holding up rather nicely in spite of the worst projections.

I have little faith in the sciency reports that came out a couple years ago during the debate on listing the polar bear under the ESA. They relied on IPCC assumptions and gave current data short shrift. So what will be the real impacts to polar bears and pinnipeds of a major decline in Arctic ice? We don’t know. We speculate, and the more extreme speculations make it into press releases and ultimately policy documents. But we really don’t have the observations required to make anything other than a WAG. The Arctic is a brutal place and it is very expensive to conduct research there. It will continue to be so, even if temperatures rise and summer ice recedes. So plan on the error bars being wildly huge for any Arctic data analysis.

The NH ice melt this year is going to be less than last years and so on. BTW the SH ice has been ABOVE anomaly for at least 2 YEARS now. Therefore if AGW exists (which it doesn’t) it ain’t even global (no.. the temp story doesn’t work either) Steig et al., completely debunked nearly everywhere.. Nature should withdraw this paper. I have published 23 papers in refereed journals. I would not even consider submitting anything to NATURE anymore!

The NH ice melt this year is going to be less than last years and so on. BTW the SH ice has been ABOVE anomaly for at least 2 YEARS now.

Reference to the CT data shows that this hasn’t even been true for the last year never mind two. Careful reading of the graph shows that what has happened for the last two years is a faster than usual regrowth for about 6 weeks followed by normal growth, the min and max both being ~normal.

Therefore if AGW exists (which it doesn’t) it ain’t even global (no.. the temp story doesn’t work either) Steig et al., completely debunked nearly everywhere.. Nature should withdraw this paper. I have published 23 papers in refereed journals. I would not even consider submitting anything to NATURE anymore!

Well I’ve published over 80 and I’d have no problem in publishing in Nature.

Out of curiosity I scaled the NSIDC Antarctic extent data to Uni-Hamburg so I could calculate a 1979-2000 daily average. Not surprisingly, the maximum and minimum extent for the 1979-2000 extent were lower than the 2003-2008 average. However, even using that average to calculate an anomaly from the Uni-Hamburg data, the extent anomaly is still negative for most of the month of September, 2008. So neither the extent nor area anomalies have been positive for two years.

I suspect the melt acceleration may be linked to the cool phase PDO. One of the factors in this increased melt has been an increase in the transpolar drift, with stronger winds pushing across the Arctic from the Bering Straight to the Atlantic pushing ice out into the Atlantic to melt.

In 2007 it has almost been like a switch has been thrown, since then we’ve seen much less ice in summer and more ice in winter. Probably a little early to say whether this is a definite pattern, or just a set of coincidences, but I think it fits well with the cool PDO phase, which started around late 2007 or early 2008.

A cool PDO causes cold temperatures in the far north pacific. Sea ice in the Bering Sea was more than 20% above the 30 year average according to Cryosphere today this past winter, and the ice pattern in 07/08 winter was similar as well if you compare archive ice maps.

A cool PDO phase also causes generally higher pressure in the North East Pacific. This will tend to promote southerlies over the West Pacific, and northerlies in America, and seems likely to me to assist the transpolar drift across the Arctic. In winter this means that the Sea of Okhotsk (NE of Japan) is receiving warmer southerlies – last winter CT shows this area as more than 20% below the 30 year average. On the American side this tendancy is pushing cold northerlies into areas around NE America. CT shows that the ice areas for Baffin, Newfoundland, Hudson Bay and St Lawrence Gulf areas were all around the 30 year average last winter.

Meanwhile in the Arctic basin the whole thing is frozen solid during winter. Increased transpolar drift bringing warmer air from Russia and North East Pacific has no effect on ice area, but maybe helping to push the ice a little faster across the Arctic and out into the Atlantic, maybe leaving it a little thinner. But with sparse thickness measurements this is probably only a guess that can’t be confirmed/refuted?

So in Winter the cool PDO tends towards increased ice area/extent in areas outside the Arctic basin, but has zero tendancy to reduce the extent/area in the Arctic.

But in Summer we have a different situation. The North Pacific and North Atlantic areas where cool PDO acts to increase ice are ice free anyway. Whereas the ice melt boundary has entered the Arctic Basin and the increased transpolar drift can suddenly have an impact. The southerly winds on the Russian side are bringing significant heat into the Arctic Basin, and the ice being partially melted is much more easily pushed around by the wind.

The other factor mentioned in explanations of the extreme melt in 2007, and which seems to be again present this year is a tendancy for high pressure north of Canada. Whether this can be connected to cool PDO or not I don’t know, as the map of PDO impacts at http://jisao.washington.edu/pdo/ doesn’t show what happens in the Arctic.

And why didn’t the last phase of cool PDO cause dramatic summer ice melt? Perhaps because we had much less AGW impact back then and the melt front spent much longer part of the year outside the Arctic Basin where cool PDO increases ice area, and much less time inside the Arctic Basin where cool PDO decreases ice area.

By the way here’s this month’s update to the source of your ‘old ice’:
“Forecast ice conditions for July 16th to July 31st.

During the second half of July, the mean temperatures will remain
near normal over most regions except above normal along the Bering
Strait and Alaska coastal regions. The ice will melt at a moderate pace
and fracture throughout the southern route of the Northwest Passage from
western Barrow Strait through Peel Sound, across Victoria Strait, Queen
Maud and Coronation Gulfs. An open water route will develop between
Mackenzie Bay and Cape Bathurst. Further west, the open drift or less
route along the Alaskan Coast between Prudhoe Bay and Barter Island will
develop and this will be 3 weeks sooner than previously forecast. Within
the Beaufort Sea ice pack, ice concentrations will slowly decrease from
very close pack to close pack conditions while open drift to very open
drift concentrations will prevail along the outer edge.”

Aww c’mon Phil. Did you read my post at 139? Here’s the exact same link showing the exact same image you “chose” above ‘cept it doesn’t help your point. For anyone else click on the link he has posted above. Then click this:

There is a veritable log jam at the 2 potential exits into the Beaufort.

Aww c’mon Phil. Did you read my post at 139? Here’s the exact same link showing the exact same image you “chose” above ‘cept it doesn’t help your point. For anyone else click on the link he has posted above. Then click this:
There is a veritable log jam at the 2 potential exits into the Beaufort.

July 7th 2009 Modis Terra image for the mouth of the Beaufort.
Compare that to the 29 June link above. Nothing much has changed.
The water off Resolute and Peel sound has been open for a long time. There is some very thick fast ice between there and Aulavik National Park on Banks Island, at the mouth of the Beaufort. Where the ice jam is. Forecast is snow/rain and around zero for the next week.

By the way here’s this month’s update to the source of your ‘old ice’:
“Forecast ice conditions for July 16th to July 31st.

Another junk journal apart (from Nature) that I don’t read anymore is the “New Scientist” re Sea levels this week see Rahmsdorf right on this blog…what a joke! Nature used to be a top Journal though… USED TO BE.

As things start to get interesting from the start of July why not do a running total from the 1st rather than daily for all years? I think you will find the results up to now interesting and it will give a better picture of the summer melt than the daily ones.

Well it is definitely melting more on the Russian side at the moment with far more open water it has to be said. Still 2 months to go though.There isn’t that much open water comparitively in the NW Passage region so you could have very low extent and it still blocked off, if you see what I mean.

Thank you all – but be aware that I’ll be away from July 20 till July 28 – holidays, buddies!
For today, simple daily figures should do it – But I think it’s great to put weekly or montlhy changes when possible. Final numbers for yesterday:

Re: Flanagan (#188),Shawn: you should take care with such simple reasonings. In 2008, the “frozen” season was quite ong also.

Nothing simple about my ideas.
The Earth is cooling and the Arctic is going to have more ice.

Come to think about it it is simple.

So was the economic meltdown. You could see it coming from a mile away and very few of the economist saw it. The consensus was very wrong and the few that correctly predicted the original economic crash are predicting another. And they will be right again. Meanwhile the consensus of economists are predicting a recovery this year. And they will be wrong.

How come a simple guy like me can figure this out and most of the worlds scientists can’t?

I have to say I sometimes think like that and it gets more so the more beer I have ! :).

The High pressure regions are staying put over the East Siberian and Beaufort seas so I expect quite a bit of melting on the Russian side and some on the other onwards. Where 2009 lags 2007 is in the ChuckieEgg sea.